Cells normally maintain a balance between protein synthesis, folding, trafficking, aggregation, and degradation, referred to as protein homeostasis, utilizing sensors and networks of pathways [Sitia et al., Nature 426: 891-894, 2003; Ron et al., Nat Rev Mol Cell Biol 8: 519-529, 2007]. The cellular maintenance of protein homeostasis, or proteostasis, refers to controlling the conformation, binding interactions, location and concentration of individual proteins making up the proteome. Protein folding in vivo is accomplished through interactions between the folding polypeptide chain and macromolecular cellular components, including multiple classes of chaperones and folding enzymes, which minimize aggregation [Wiseman et al., Cell 131: 809-821, 2007]. Whether a given protein folds in a certain cell type depends on the distribution, concentration, and subcellular localization of chaperones, folding enzymes, metabolites and the like [Wiseman et al.]. Human loss of function diseases are often the result of a disruption of normal protein homeostasis, typically caused by a mutation in a given protein that compromises its cellular folding, leading to efficient degradation [Cohen et al., Nature 426: 905-909, 2003]. Human gain of function diseases are similarly frequently the result of a disruption in protein homeostasis leading to protein aggregation [Balch et al. (2008), Science 319: 916-919].
Dysfunction in proteostasis has been implicated in a diverse range of diseases including for example, neurodegenerative disease, metabolic diseases, inflammatory diseases and cancer. There remains a need in the art for compounds and pharmaceutical compositions to treat conditions associated with proteostasis dysfunction.